diff options
| -rw-r--r-- | tools/perf/tests/dwarf-unwind.c | 36 | ||||
| -rw-r--r-- | tools/perf/util/unwind-libunwind.c | 28 |
2 files changed, 61 insertions, 3 deletions
diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c index ab28cca2cb97..0bf06bec68c7 100644 --- a/tools/perf/tests/dwarf-unwind.c +++ b/tools/perf/tests/dwarf-unwind.c @@ -11,6 +11,9 @@ #include "thread.h" #include "callchain.h" +/* For bsearch. We try to unwind functions in shared object. */ +#include <stdlib.h> + static int mmap_handler(struct perf_tool *tool __maybe_unused, union perf_event *event, struct perf_sample *sample __maybe_unused, @@ -28,7 +31,7 @@ static int init_live_machine(struct machine *machine) mmap_handler, machine, true); } -#define MAX_STACK 6 +#define MAX_STACK 8 static int unwind_entry(struct unwind_entry *entry, void *arg) { @@ -37,6 +40,8 @@ static int unwind_entry(struct unwind_entry *entry, void *arg) static const char *funcs[MAX_STACK] = { "test__arch_unwind_sample", "unwind_thread", + "compare", + "bsearch", "krava_3", "krava_2", "krava_1", @@ -88,10 +93,37 @@ static int unwind_thread(struct thread *thread) return err; } +static int global_unwind_retval = -INT_MAX; + +__attribute__ ((noinline)) +static int compare(void *p1, void *p2) +{ + /* Any possible value should be 'thread' */ + struct thread *thread = *(struct thread **)p1; + + if (global_unwind_retval == -INT_MAX) + global_unwind_retval = unwind_thread(thread); + + return p1 - p2; +} + __attribute__ ((noinline)) static int krava_3(struct thread *thread) { - return unwind_thread(thread); + struct thread *array[2] = {thread, thread}; + void *fp = &bsearch; + /* + * make _bsearch a volatile function pointer to + * prevent potential optimization, which may expand + * bsearch and call compare directly from this function, + * instead of libc shared object. + */ + void *(*volatile _bsearch)(void *, void *, size_t, + size_t, int (*)(void *, void *)); + + _bsearch = fp; + _bsearch(array, &thread, 2, sizeof(struct thread **), compare); + return global_unwind_retval; } __attribute__ ((noinline)) diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c index 371219a6daf1..6edf535f65c2 100644 --- a/tools/perf/util/unwind-libunwind.c +++ b/tools/perf/util/unwind-libunwind.c @@ -185,6 +185,28 @@ static u64 elf_section_offset(int fd, const char *name) return offset; } +#ifndef NO_LIBUNWIND_DEBUG_FRAME +static int elf_is_exec(int fd, const char *name) +{ + Elf *elf; + GElf_Ehdr ehdr; + int retval = 0; + + elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); + if (elf == NULL) + return 0; + if (gelf_getehdr(elf, &ehdr) == NULL) + goto out; + + retval = (ehdr.e_type == ET_EXEC); + +out: + elf_end(elf); + pr_debug("unwind: elf_is_exec(%s): %d\n", name, retval); + return retval; +} +#endif + struct table_entry { u32 start_ip_offset; u32 fde_offset; @@ -322,8 +344,12 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi, #ifndef NO_LIBUNWIND_DEBUG_FRAME /* Check the .debug_frame section for unwinding info */ if (!read_unwind_spec_debug_frame(map->dso, ui->machine, &segbase)) { + int fd = dso__data_fd(map->dso, ui->machine); + int is_exec = elf_is_exec(fd, map->dso->name); + unw_word_t base = is_exec ? 0 : map->start; + memset(&di, 0, sizeof(di)); - if (dwarf_find_debug_frame(0, &di, ip, 0, map->dso->name, + if (dwarf_find_debug_frame(0, &di, ip, base, map->dso->name, map->start, map->end)) return dwarf_search_unwind_table(as, ip, &di, pi, need_unwind_info, arg); |